Expander spring for piston rings



Nov. 8, 1932. E. G. BUCHMANN v EXPANDER SPRING FOR PISTON ilINGS Filed April 23, 1932 u 1 III Illlll'l" Illlll HIIIII A E I IN VENTOR EDWARD 6. BUCHMfi/YN AA a. 6mm

A TTORNEY Patented Nov. 8, 1932 I v 7 i w D?STAT-Es PFFwE I V MANN, onms'r j LINQ IS it 7 I EXPAND: IN s arred; ma filed P111793, 2. sflf a ino. 507.106." I: inventioii lilatsito expand Spring-s Section ota'mOdification-of. 1 showing a having channelsand oil Passages, trans-splitv section of piston ring andexpander p ng. 7

piston rings with oil apertures and-trans-split "Referring to the drawing: A piston 10 pistonrings of that type which are slotted having onezor more annular piston ring I: 5 so as to contract in'width when assembled in grooves of which one groove 11 has an oil 'cess of friction between the piston ring and :and the latter to the annular piston ring groove of the passage 12 therein, leading to the-interior of "piston; thepiston-as usual, witha piston ring 13'hav- This invention is in part, an improvement 'ing oil aperturesl l, assembled or mounted on my pending applicationfiled October 1, within the said groove '11; Mounted within 1931, Serial No. 566,212. V 7 the groove, behind the pistonringli, is an C One objectot theinvention is to provide: expander spring 15 withoil vents 16 cut into means'for registeringoil vents of expander the edge ofsaid expander spring to receive springs with all of the oil passages in the :thefflOW Of oil-from the oil passages in the enti're circumference of an annular piston plston ring 13-and convey the oilto the pasring groove of a piston. f sages 12 and into the-hollow piston 10. a i Another object is to providea novel form f The modification shown in Fig.2 has a 'of expander spring whose cross-section is difference only inthe piston ring 13a which similar to that of the letter I andforms. 5111- has slots 17 cutopposite each other instead of nular oil channels forthe freepassage of oil being on each side of the tongue as are slots F 20 around the entire circnmferenceof the pisor oilnapertures 14 in Fig. 1. These slots are 16 ton ring groove. and saidspring is normalmilled with aradiu's at 14a; and 17a to prevent ized', after forming the bends, by heat treatharp corners andthus avoid breaking ing to reset the spring tension of the metal. The modification shown g- 3 has it Still another object is to provide an exd fference only lIlthe oil vents 16a whichare pander springthatis more resilient against; On themiddle lin'e of the'expanderspring 15w 7- the moving element or piston ring, this 610- ins ad of being in the lower edge as shown ject being attained by havingthe outer curva- 'i tig 1 at 1 ture of the spring of agreater radiusthan :F1gs.4 and5 illustrateditferentjbent forms the inner curvature, which prevents and ex- -0f jthefsprings, the former 'being'hexagonal eing waved or corrugated the cylinder wall thus causing a minimum of lengthwise. V I v Wear on the said cylinder wall, V I 'a The modified form of expander spring 18 1 Other ob 'ects and advantageswill benoted- Shown in Fi'Q'f 6 h s a difi'eren'ce in shape from the following description and the ac- Ionly, as have the modified forms 25,26 and 27 Figure 1 is a partial section and elevation being characterized byannular channels or of a trans-split piston ring and expansion 1 concavities on one orboth sides.

- spring; Fig. 2 is a side elevationof a modified .1 Thepiston ring 19 h WII' iII Fig 10 i fform'of the piston ring shown in Fig. 1; ferent onlyin the position of the oil passage. Fig. 3 is a sectional view of a modified form 20. I p l I 96 of the expansion spring shown in Fig. 1; Fig. -Theinner surface 21 of the piston rings 13 1 is a longitudinal sectional fragment of Fig. or 19 is-rough'machined or file-like and en- 3; Fig. 5 is a sectional fragnientsimilar to gagesthe'ribs or curved surface 22 0f the Fig. 4: but with a curved surface; Fig. 6 is a expander springs" 15 and-15a and thus prea modified form of Fig. 6 with one side conin an axial direction, and alsopreventa rock-' cave and the other sidestraight; Fig.8 is a ing motion of the piston-ring within the pismodified form of Fig. 7 showing both sides ton ring groovell. 1 f concave; Fig. 9 is a modification of Fig.6 Among the advantages offithe typesfdesimilar to Fig. 7 Fig. 10 is a fragmentary scribed are the following: After the springs companying drawing, in which: Shown in F igs.7 8 and 9 respectively, all

section taken on line 66 of Fig. 3; Fig. 7 is vents the piston rings 13 or 19 from collapsing are bent or formedthey are ,normalized by heat treatment so as to reset the spring tension of the metal, and the outer curvatures what like the letter I, or the modifications shown, forms longitudinal poil channels for ference of the ring and the groove, and the .ports or openings in the spring allow this oil to freely flow to the passages leading to the inside of the piston. This is desirable because manufacturers of pistons difi'eras to the munber of passagesleading from the groove. The present-spring is believed to be the first expander spring to disclose means for uncov e'ring allof the oilpassages'around the full circumference of the pistonring groove.

An improved feature of the ring itself is i that a doubletongue and groove joint is pro vided, thereby doubly sealing the split in Y the ring against loss of compression and gas leaks. 1 V A further feature of advantage is that the present ringis slotted with a milling cutter soas to form the slots without sharp ends or corners, therebyv avoiding the breaking. or

separation of the piston ring into sections, which is apt to occur with rings made of light gray iron slotted with a cutter producing sharp ends or corners, which readily break 7, when in use, or cause the'middlepart to sepa- 1 rate from the top and bottom parts.

, --The inner surface 21 of the ring .is rough machined, or made somewhat similar to a file,-

and this roughened-surface contacts with the enlarged ribs or edges'of the spring andprevents theroeking or collapsing of the piston ring in an axial direction, which would otherwise be apt to occur in consequence of the drag of the-ring against the cylinder wall on the v in and out stroke ofthe piston.

It will be understood that the passages 15, if

or concave side walls of the spring, together 4. An expander spring for piston rings, thickest at its longitudinal edges, thereby forming 'a longitudinal channel extending around the spring between said edges.

5. An expanderspring for piston rings, thickest along its longitudinal edges, and thinnest between said edges, forming longitudinal passages on opposite sides, and ports connecting said passages. 6. An expander spring as 1n claim 5, sa1d ports extending throughthe thin portions.

, ,7. The combination stated in claim 5, said ports "extending through one of the thickest edges. the free passage of oil around the full circum-' 8. The combination with a slotted piston ring having a roughened inner surface, of an expander spring having edges engaging said surface to; prevent axialcompressing of the rin c j 7 9 The combination with a piston ring having upperand lower roughened surfaces extending around the inside thereof, of an expander springhaving projecting edges engaging said roughened surfaces to prevent axial compression of the rings *10. A trans-split slotted piston ring flexible on the width, with'the-slot-s beveled at the ends thereof, having a tongue and groove joint, and the piston ring having a roughened inner surface, of anexpander spring having edges engaging said surface'to prevent axial compression on the width of the ring, said expander spring having oil passages.

' In testimony whereof, I do aifix my signature.

EDWARD G. BUCHMANN.

with the notches 16 or holes 16a permit a relatively free flow of oil springs.

I claim:

through and around the i I 1. ;An expander spring for piston rings,

ha-ving anioil channel extending along one side thereof and oil ports in the spring com- 7 municating with said channel.

.2 An expander spring for, piston rings, having oil channels extending along opposite sides thereofand oilports therein connecting said channels.

3. An expander spring for piston: rings, substantially I-shaped in cross section. 

